Epichlorohydrin is a key ingredient in the preparation of glycidyl products and epoxy resins. Epichlorohydrin is also suspected of being a carcinogen. Accordingly, it is imperative for considerations of health, safety and economic prudence that the epichlorohydrin content of epoxy resin and glycidyl products be reduced to the lowest feasible levels to minimize any hazards involved with residual epichlorohydrin.
Conventional methods to strip epichlorohydrin from epoxy resin or glycidyl products include steam stripping, inert gas purging or falling film evaporation. However, none of these methods is satisfactory for thermally or hydrolytically unstable materials. Steam stripping clearly cannot be used with products which are not stable at high temperature in the presence of water. Gas purging or falling film evaporation can only reduce the epichlorohydrin level in thermally unstable products to a level of a few hundred ppm, still far too high for acceptability.